Microbial Transformation Of Organic Matter Of Sod-Podzolic Soils In The Pre-Urals Under Conditions Of Different Use And Application Of Mineral Fertilizers

Microbiological parameters and character of transformation of humic substances of sod-podzolic soil at the end of five rotations of eight-full crop rotation in long-term stationary field experiment (1978-2017) are investigated. The direction of microbiological processes due to the effect of long-term application of mineral fertilizers in increasing doses - 30 to 150 kg/ha of NPK was determined. A comparison of the arable soil with its virgin analogs (mixed forest and natural meadow) as well as with the planting of goatling (Galegae orientalis L.). It was found that the different use of sod-podzolic soil led to a change in the direction of soil microbial processes. Plowing the soil reduced the content of total humus and increased the number and variety of actinomycetes involved in the mineralization of semi-decomposed plant residues, i. e. detritus. In the variants with application of mineral fertilizers for cereal crops in doses 90-150 kg/ha of NPK it was observed the preservation of the original content of humus and a decrease of the index of pedotrophy compared to virgin counterparts and arable soil without fertilizers or treated with fertilizer in low doses. With the long-term cultivation of perennial leguminous culture without applying fertilizers, a microbial community is formed in the soil which is close in terms of quantitative and qualitative indicators to the microbial community of virgin soil analogs and its humus state is stabilized.